When firefighters arrive on the scene of a typical fire, the first priority is to knock down the flames in order to limit the damage being done by the fire. This is accomplished in the most expeditious manner by directing a large volume of water, at a high rate of flow, directly onto the fire. This high volume, high flow of water will quickly suppress the majority of the fire by removing oxygen and by reducing temperature. Once the majority of the flames have been knocked down, which usually occurs in the first few minutes after the arrival of the firefighters on the scene, the bulk of the time is spent overhauling the fire site by putting out small stubborn fires, extinguishing smoldering debris and ensuring that the fire is completely extinguished. The attack nozzle is not specifically suited for such a task. It wastes water, damages property, exposes the firefighters to unnecessary risk of injury, destroys possible evidence of criminal activity and is generally unsatisfactory for the task.
A typical attack nozzle that is attached to a conventional fire hose can discharge 50 to 150 gallons of water per minute. In the initial stages of a firefighting operation, this high volume, high flow rate of water, or another fire suppressing liquid, is critically important. The large amount of water will usually knock down the large percentage of flames at a fire scene. However, once the flames have been so knocked down, the firefighters have little recourse but to continue to discharge 50 to 150 gallons of water per minute to put out smoldering debris and to be sure that the fire is completely out.
A prolonged, high volume use of water is unnecessary and is often more destructive than the fire itself. In the majority of fires, the bulk of the property damage is caused by water damage not by the flames themselves. In a multi-story dwelling or in a multi-unit structure, a fire in one room or in one apartment often will have fire damage that is limited to that one area. However, the discharge of large volumes of water, well after the initial fire has been controlled, and for the purpose of putting out any hot spots, results in very substantial water damage. In a number of instances, up to 80 percent of the time at a fire scene is devoted to the overhauling or extinguishing of such hot spots. It is not necessary to use a flow of 50 to 150 gallons of water per minute to put out smoldering debris. Lower rooms of a dwelling or apartments on lower floors of a building sustain substantial water damage as a result of this use of far more water than is necessary.
A fire hose that is filled with high pressure water is dangerous to the fireman who has to drag it from location to location in a room in a building and from room to room. If the attack nozzle is not held securely, it can escape from the grip of the firefighter and can become a deadly object flailing around in a room. A length of typical fire hose, filled with high pressure water, is heavy and difficult to move. A large number of injuries that are sustained by firefighters are a result of the exertion which is required to move a heavy line from place to place within a room. At the same time, it is not safe to remove the large line in favor of a replacement small line that is lighter in weight and that has reduced flow capabilities. No fire is ever safe until it is fully extinguished and cold. It is always possible that the fire will reignite in a flashover that can easily cause serious injury or death. For that reason, it is not a reasonable course of action to replace a large fire line and an attack nozzle with a smaller line. The firefighter needs the safety that can be provided, if needed, by the high volume supply of water provided by a main line and an attack nozzle.
The cause of a fire is always a concern. In the investigation of a fire site by a fire marshal or other personnel, the prolonged use of an attack nozzle, beyond the time required to knock down the initial fire, will often result in the destruction of potential evidence which could have benefited the investigator in his determination of the cause of the fire. If some type of liquid accelerant was used to start a fire, the more it is diluted by large quantities of discharged water, the more difficult it is to detect. When the fire is a result of a faulty appliance, bad wiring, a candle that was left unattended, or any other cause, the destructive force of high pressure water sprays provided by a typical attack nozzle will make the investigator's job that much more difficult. Once the initial fire has been knocked down and controlled, the continued use of the attack nozzle to control hot spots and to put out small fire sites will render the fire scene that much more difficult to investigate.
It will be readily apparent that a need exists for an alternative or an adjunct to the use of a main line and an attack nozzle in the course of a firefighting operation. The overhaul line system in accordance with the present invention provides such an alternative or adjunct and is far superior to the prior art.